1. Field of the Invention
This invention relates to a medicinal aerosol formulation, and more particularly, to a medicinal aerosol formulation comprising a troglitazone and a protective colloid stabilizer.
2. Description of the Related Art
Delivery of drugs to the lung by way of inhalation is an important means of treating a variety of conditions, including such common local conditions as cystic fibrosis, pneumonia, bronchial asthma and chronic obstructive pulmonary disease and some systemic conditions, including pain management, immune deficiency, hormonal therapy, erythropoiesis, diabetes, etc. Anti-diabetic drugs, e.g. an insulin, are among the drugs that are administered to the lung for such purposes. Such drugs are commonly administered to the lung in the form of an aerosol of particles of respirable size (less than about 10 xcexcm in diameter). In order to assure proper particle size in a liquid aerosol, particles can be prepared in respirable size and then incorporated into a colloidial dispersion containing either a propellant, as a pressurized metered dose inhaler (MDI) or air such as in the case of a dry powder inhaler (DPI). Alternatively, formulations can be prepared in solution or emulsion form in order to avoid the concern for proper particle size in the formulation. Solution formulations must nevertheless be dispensed in a manner that produces particles or droplets of respirable size.
For MDI application, once prepared an aerosol formulation is filled into an aerosol canister equipped with a metered dose valve. In the hands of the patient the formulation is dispensed via an actuator adapted to direct the dose from the valve to the patient.
What is needed and desired is a stable aerosol formulation for the treatment of diabetes and conditions related thereto comprising troglitazone or its pharmaceutically acceptable derivatives or salts, e.g. maleate.
It has surprisingly been found that a novel and stable medicinal aerosol formulation of troglitazone, e.g. its maleate, can be obtained without the use of either cosolvents, such as ethanol, or surfactants, such as sorbitan trioleate which are typically added to a binary aerosol formulation. Such stable medicinal aerosol formulations are obtained by the use of a protective colloid stabilizer.